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Researchers: Genetic mutation against malaria is not random


The study concerned higher rates of anti-malaria mutations that, when present in two copies, leads to sickle cell disease. Ghanaian men were more likely to have the mutation than European men. The researchers thought this was not due to chance.

New research challenges the overarching assumption that genetic mutations occur randomly and are then either kept or discarded by natural selection. In the study, published January 14 in Genome Research, scientists found that the rate of a specific mutation with important health implications is nonrandom, occurring more or less often in different populations that have experienced specific environmental pressures over the course of generations…

Because the study focused on sperm samples, which are equivalent to a single generation, natural selection and genetic drift had no influence on the prevalence of mutations, Livnat tells The Scientist. And given the medical importance of the mutation exhibiting increased occurrence in the African cohort, Livnat says the results “raise a fundamental challenge to the notion of random mutation.”

Dan Robitzski, “Study: Sickle Cell Mutation Driven by Pressure, Not Random Chance” at The Scientist (March 17, 2022)

Robitzski goes onto report that this finding is not popular with researcher Adi Livnat’s colleagues.

But Livnat is standing his ground:

“I do not think it is a coincidence that the HbS mutation, which provides protection against malaria, originates de novo more frequently in sub-Saharan Africans than in Europeans,” Livnat says. “I also do not think it is a coincidence that it originates more frequently in the gene where it provides this protection compared to the nearly identical nearby delta globin gene, where precisely the same mutation could happen but would not provide protection.”

Dan Robitzski, “Study: Sickle Cell Mutation Driven by Pressure, Not Random Chance” at The Scientist (March 17, 2022)

The paper is open access.

ID proponent Michael Behe, of course, discusses the malaria–sickle cell situation at some length in Edge of Evolution. We hope that’s not enough to shut down the discussion or endanger Livnat’s career.

Great posts 1-3, PaV! With the freedom to follow scientific evidence without ideological imperatives, Darwinism might some day be viewed as having the same stultifying effect on science as once did Aristotelianism. -Q Querius
This seems to point to the immune system directly controlling specific epigenes for intergenerational immunity. Weather has several long-term cycles. The dominant one is about 33 years, which would be well served by epigenes that last two or three human generations. polistra
swinging like a pendulum as environmental conditions changed
With organisms unchanged for millions of years. All sorts of calculations for fixation rates are blown away.
adaptation of multiple fitness associated phenotypes on the same timescale as the environmental change
since evironmental changes are cyclical, there would be no linear path for new traits to develop. Adaptation would be cyclical; adjustments for environment, and never enough stability to create new complex features (or need such). Silver Asiatic
From the preprint of the Science paper:
Overall, our results show that strong and temporally variable natural selection can consistently drive rapid and polygenic adaptation of multiple fitness associated phenotypes on the same timescale as the environmental change.
Or, (which conforms with so much other data) mutations are being "directed" via an environmental feedback system. Again, NS is no more than a "sieve," and nothing more. In fact, it's hardly a "sieve." PaV
Just in today: From Phys.Org, here's this tidbit:
But what made the findings particularly compelling was that the direction of adaptation changed multiple times, swinging like a pendulum as environmental conditions changed. "To think that a trait could evolve over a certain number of weeks, and then reverse direction the following month, that was very surprising," Rudman says. "This paints a picture of adaption and selection being really dynamic. The direction of natural selection is changing, the targets are changing, and they're changing really quickly."
Again, scientists are surprised. There is nothing left of Neo-Darwinism. There is nothing left of Darwinism. Except biology faculties around the world and Nature. PaV
If mutations are directed--and there is substantial proof that they are, then NS is nothing more than a sieve. End of story. PaV

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